Afghan and NATO-led troops killed up to 70 insurgents in a battle involving attack helicopters and air support while an ISAF soldier was killed in a bomb blast, the force said on Sunday.
The separate incidents occurred Saturday in the southern province of Uruzgan, where the International Security Assistance Force (ISAF) has based Australian and Dutch soldiers in the battle to rid the country of Taliban insurgents.
ISAF and Afghan National Army troops were attacked by between 100 and 150 insurgents near a base in the province, the force said in a statement.
"In a firefight lasting several hours, the insurgents were engaged by ISAF and (Afghan) small-arms fire, attack helicopters and close air support," it said.
"Initial battle damage assessment indicates that up to 55 insurgents were killed." An Afghan soldier was wounded.
ISAF spokesman Major Luke Knittig said later that battle damage assessment in daylight put the number of dead "at closer to 70".
"We know that insurgents have been seeking to use north Uruzgan as a safe haven and we have been taking action," he said. "They initiated the action but we were there with a purpose and ready for them."
In the second encounter, an ISAF convoy was struck by a bomb. One soldier was killed and one wounded, another statement said.
The force does not release the nationalities of its casualties until this information has been made public by the home countries.
"Two civilians and a local national were also injured in the attack. The casualties have been evacuated to an ISAF medical facility for treatment," the statement said.
ISAF has 31,000 troops from 37 countries across Afghanistan trying to help local authorities establish security five years after the Taliban were removed from power.
The foreign soldiers have faced virulent resistance, especially in the south and along the border with Pakistan, where many Taliban are believed to have fled after their regime was toppled for sheltering al Qaeda members.
More than 110 international soldiers have been killed in action in Afghanistan this year. ISAF said last week it had lost 41 soldiers in action.
The battle was in the north of the Uruzgan capital, Tirin Kot, one of several places that NATO military commander General James Jones visited in a three-day trip that ended Saturday after he was presented with Afghanistan's highest honour for services to the country.
Jones said the injection of extra troops in the south with ISAF's take-over of the region in July had provoked a reaction by stirring up entrenched militants and criminals.
"Since July we have been able to put as many as 9,000 NATO troops in the south and what has happened there is we have disturbed some traditional sanctuaries," Jones told reporters.
"We have upset the narcotics drugs business, we have upset the criminal elements, we have upset any number of things that are acting as cancers in the recovery of Afghanistan."
Jones said he had seen passion shown during his tour for putting Afghanistan on a better path.
"We are dedicated as a family of nations to being successful in Afghanistan and that is what motivates us... that is why I think this passion is real and sincere and will drive us to a successful state in the not-too-distant future."
Jones also apologised for the killing of civilians in a NATO air strike in the southern province of Kandahar late Tuesday.
ISAF and government teams are investigating how many people were killed in the raid, which targeted Taliban fighters. Seventy people died in a day of clashes and 12 were confirmed to be civilians, the force has said.
Local residents have said between 60 and 80 civilians were killed and none of the dead was a Taliban.